Two women arrested on suspicion of conspiracy to murder British soldier Lee Rigby (25) in London on Wednesday have been released without charge, Scotland Yard has said.

A 29-year-old was arrested yesterday in connection with the killing and today the force revealed that another woman, aged 31, had been held at a home in south London around 11.50pm last night and later released.

Detectives are continuing to question a 29-year-old man on suspicion of conspiracy to murder Drummer Rigby, who was hacked to death in Woolwich, south-east London on Wednesday.

The two men who were shot by police after charging towards armed officers brandishing weapons remain in hospital in a stable condition.

They were arrested on suspicion of murder on the day of the attack.

The tearful family of the murdered soldier said today “our hearts have been ripped apart”.

Rigby’s wife Rebecca (30), mother of his son Jack, aged two, and stepfather Ian Rigby( 54), fought back tears as they spoke on behalf of the 25-year-old’s whole family at a press conference at the Regimental HQ of his unit, the Royal Regiment of Fusiliers in Bury, Greater Manchester.

The soldier’s mother Lyn Rigby (46), sat red-eyed, unable to speak through tears, clutching a teddy her son had bought his child.

Sobbing, Rebecca Rigby said: “I love Lee and always will. I am proud to be his wife and he was due to come up this weekend so we could continue our future together as a family.

“He was a devoted father to our son Jack and we will both miss him terribly.”

Asked about the shock of the attack being on British soil, she added: “You don’t expect it to happen when he’s in the UK. You think they’re safe.

“His proudest moments were serving in London on the ceremonials with the drum corps.”

British MPs are to investigate the brutal killing following the disclosure that the two suspects were known to MI5.

British prime minister David Cameron parliamentary Intelligence and Security Committee chaired by former foreign secretary Sir Malcolm Rifkind would investigate the killing.

The two men detained in Woolwich, one of whom has been named as Michael Adebolajo, are both in a stable condition in separate hospitals and their injuries are not life-threatening.

Police investigating the incident yesterday arrested two more people and raided six homes.

Officers have begun to trawl through CCTV footage gathered in Woolwich, along with information posted by witnesses online.

Today, Muslims throughout Britain will gather as normal for Friday prayers, amid fears that scores of minor attacks on mosques late Wednesday and early yesterday could escalate.

However, prime minister David Cameron issued pointed declarations for calm, saying the attack was “a betrayal” of Islam and of the Muslim communities “who give so much to our country”.

Mainstream Muslim organisations condemned the Woolwich atrocity, with the Muslim Council of Britain saying it was “dishonourable”.

Mr Adebolajo and his unnamed companion had come to the attention of British intelligence services in recent years, but had not been regarded as imminent threats.

The 29-year-old Adebolajo, raised as a Christian to Nigerian parents, had converted to Islam as a teenager, becoming more radical as time went on. Having joined an extremist organisation, the now banned al-Muhajiroun, he took part in a number of public demonstrations about British policy in Iraq and Afghanistan.

Last night, one of the leaders of al-Muhajiroun, Anjem Choudary, refused to apologise for any role that he played in converting Adebolajo to extreme views.

The mayor of London, Boris Johnson, said questions will have to be asked about Islamic extremism but “it is very, very important that we don’t blame the religion of Islam”.

Taking action to prevent the killing of a soldier outside Woolwich Barracks would have been “incredibly hard”, a former senior intelligence officer has said. Richard Barrett, ex-head of counter-terrorism at MI6, said the two attackers were unlikely to have had the wider connections which would have caused the security services to investigate them more deeply.

But Mr Barrett said there have may been little that MI5 could have done to prevent an attack which required little planning or preparation. “I think it is incredibly hard to stop,” he told BBC2’s Newsnight.

“I assume that these people are probably coming out of a small group without necessarily any overseas connections or any other broader connections in the United Kingdom which could come to the attention of the security services more than they did.

“When does a person who expresses radical views, who joins a radical group, flip over to over to be a violent extremist? To find the signals, the red flags as it were, I think is enormously hard.

“I should imagine that these two people themselves probably didn’t have any intention to commit a crime like this until relatively recently before they did. “They must have had some indication that these guys were a problem in order to note their names. But it is one thing to note their names, it is quite another thing to take invasive action to track their movements and so on.”